000
AGXX40 KNHC 161853
MIMATS

MARINE WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
253 PM EDT WED SEP 16 2015

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN
SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND
64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS.
 

...GULF OF MEXICO...

MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL WITH
MANUAL EDITS. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES.
MEDIUM CONFIDENCE.

AN INVERTED SURFACE TROUGH THAT MOVED ACROSS THE STRAITS OF
FLORIDA INTO THE SE GULF YESTERDAY HAS COME INTO PHASE WITH A
SHARP UPPER TROUGH EXTENDING FROM THE TENNESSEE VALLEY TO THE
NORTH CENTRAL GULF. THIS PATTERN IS MAINTAINING AREAS OF SHOWERS
AND THUNDERSTORMS ACROSS THE EASTERN GULF AND FLORIDA PENINSULA.
THE UPPER TROUGH WILL BECOME MORE AMPLIFIED AS IT DRIFTS EAST OF
THE GULF THROUGH LATE FRI. THE 12Z GFS AND ECMWF ARE IN BETTER
AGREEMENT AND CLOSER TO ENSEMBLE MEANS COMPARED TO EARLIER RUNS
SHOWING WEAK TROUGHING PERSISTING FROM THE NE TO SW GULF INTO THE
WEEKEND...SHIFTING EASTWARD THROUGH EARLY NEXT WEEK. THIS IS IN
CONTRAST TO THE UKMET AND CMC WHICH REMAIN MORE AGGRESSIVE.

...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...

MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS
BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE.

THE COMBINATION OF A TROPICAL WAVE MOVING ACROSS THE CENTRAL
CARIBBEAN AND A WEAK AND DISPLACED SUBTROPICAL RIDGE TO THE
NORTH IS RESULTING IN A RELATIVELY WEAK PRESSURE GRADIENT OVER THE
CARIBBEAN BASIN CURRENTLY. WINDS ARE PEAKING AROUND 20 KT IN THE S
CENTRAL CARIBBEAN...WITH MUCH LIGHT FLOW NOTED
ELSEWHERE...ESPECIALLY IN THE NW CARIBBEAN. SEAS ARE 5 TO 7 FT IN
THE S CENTRAL CARIBBEAN AND 3 TO 5 FT ELSEWHERE. LITTLE CHANGE IS
EXPECTED IN THE PATTERN INTO EARLY NEXT WEEK WITH LITTLE
DIFFERENCE IN MODEL OUTPUT.

...SW N ATLANTIC INCLUDING THE BAHAMAS...

MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS
BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. MEDIUM CONFIDENCE.

AREAS OF CONVECTION ARE FLARING OFF THE EAST COAST OF FLORIDA THIS
AFTERNOON...ENHANCED IN PART BY AN UPPER TROUGH SITUATED WEST OF
THE REGION. GLOBAL MODELS ARE IN BETTER FOCUS INDICATING SURFACE
TROUGH MOVING EASTWARD FROM THE EASTERN GULF ACROSS THE FLORIDA
PENINSULA INTO THE WESTERN ATLC THROUGH THE REMAINDER OF THE WEEK.
SOME UNCERTAINTY PERSISTS STARTING THIS WEEKEND PERTAINING TO THE
POSSIBLE DEVELOPMENT OF LOW PRES ALONG THIS TROUGH. THE GFS
INDICATES A LOW FORMING OFF THE CAROLINAS BY EARLY SAT...WITH THE
UKMET AND CMC MORE AGGRESSIVE AND FARTHER SOUTH. THE OFFICIAL
FORECAST REFLECTS THE GFS APPROACH...WHICH IS MORE IN LINE WITH
THE ECMWF AND ENSEMBLE MEANS. THE NET IMPACT AT THE SURFACE WILL
BE OVERALL LIGHT TO MODERATE WINDS AND SEAS WITH PERIODS OF
SHOWERS AND THUNDERSTORMS PERSISTING W OF 70W INTO EARLY NEXT
WEEK. 
 
$$

.WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE
COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE:

.GULF OF MEXICO...
     NONE.

.CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN
55W AND 64W...
     NONE.

.SW N ATLANTIC INCLUDING THE BAHAMAS...
     NONE.

$$

*FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT:
HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF

NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE
NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT:
HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP

FOR ADDITIONAL INFORMATION PLEASE VISIT:
HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE

$$

.FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.